Revert "roll: go"

This reverts commit c1bb53d99250663476d5ea798ccb141b82c2e54c.

Reason for revert: didn't update roller config correctly so this CL
actually rolls back the go version. Will fix the roller config now.

Original change's description:
> roll: go
>
> From: version:2@1.16.3
> To: version:1.13.5
>
> CQ-Do-Not-Cancel-Tryjobs: true
> Roller-URL: https://ci.chromium.org/b/8847065134488199264
> Cq-Cl-Tag: roller-builder:go-roller
> Cq-Cl-Tag: roller-bid:8847065134488199264
> CQ-Do-Not-Cancel-Tryjobs: true
> Change-Id: Ia25bef86f55b9460643f285a4cea6b85f517c2a6
> Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/44222
> Reviewed-by: Pigweed Roller <pigweed-roller@pigweed.google.com.iam.gserviceaccount.com>
> Commit-Queue: Pigweed Roller <pigweed-roller@pigweed.google.com.iam.gserviceaccount.com>

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I961e8c930c390f2133e1c7e8f8cdbb70abd943c6
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/45780
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
Reviewed-by: Alexei Frolov <frolv@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json b/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json
index 42c14e6..2ca677c 100644
--- a/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json
+++ b/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json
@@ -59,7 +59,7 @@
   {
     "path": "infra/3pp/tools/go/${platform}",
     "tags": [
-      "version:1.13.5"
+      "version:2@1.16.3"
     ]
   },
   {